DEBT

A summary of long-term debt is as follows:



(In thousands)	December 31, 2014		September 30, 2014
6.5% Senior Notes due 2020 ("Senior Notes")	$	656,834	$	657,122
Revolving Credit Facility	1,085,000		1,085,000
Total long-term debt	$	1,741,834	$	1,742,122

Senior Notes

As of December 31, 2014, our Senior Notes had an aggregate principal amount of $650 million. Our Senior Notes are unsecured obligations and are not guaranteed by any of our subsidiaries. We received a premium of $8.5 million as part of the net proceeds for the Senior Notes issued. This premium is being amortized over the life of our Senior Notes.

Revolving Credit Facility

As of December 31, 2014, we had $1.1 billion of outstanding borrowings and $5.9 million letters of credit issued under our senior secured revolving credit facility, which will mature May 2018 (the "Credit Facility"). Borrowings under the Credit Facility bear interest at the Eurodollar rate plus a margin ranging from 1.75% to 2.00% and the commitment fee on the unused portion of the underlying commitment ranges from 0.30% to 0.40% per annum, in each case based on our corporate credit ratings. Our Credit Facility is secured primarily by first preferred mortgages on nine of our active drilling units as well as liens on the equity interests of our subsidiaries that own, directly or indirectly, such drilling units. Our Credit Facility contains various financial covenants and as of December 31, 2014, we were in compliance with those covenants.

The weighted-average effective interest rate on our long-term debt was approximately 2.3% per annum at December 31, 2014. The effective rate was determined after giving consideration to the effect of our interest rate swaps accounted for as hedges and the amortization of premiums or discount. Interest capitalized for the three months ended December 31, 2014 and 2013 was approximately $4 million and $10 million, respectively. As of December 31, 2014, we had approximately $459 million available for borrowings under the Credit Facility.

Short-term Debt

As of December 31, 2014, our short-term debt was $6.0 million and was incurred in financing our primary insurance program covering against casualty and liability risks. The current financing arrangement bears an interest rate of 1.57% and is amortizing over a period of nine months.